Synthesis of CoCrFeO4-chitosan beads sun-light-driven photocatalyst with well recycling for efficiently degrading high-concentration dyes

It is highly desired to develop an efficient large surface area CoCrFeO4-based beads sun-light driven photocatalysts with excellent recycling features for degrading high-concentration dyes. Herein, a novel CoCrFeO4 oxide nanoparticles have customarily been synthesized by the combination of three metals (Co, Cr and Fe) via co-precipitation method in aqueous solution and then millimeter-scale CoCrFeO4 oxide chitosan-composite beads (CoCrFeO4-CB) were prepared by incorporating the CoCrFeO4 in chitosan polymer in basic medium, which makes the adsorbent easier to separate. The number of optimized nanocomposite beads used for the removal of high-concentration dyes displays 5-time photoactivity enhancement under sun-light irradiation compared to pristine CoCrFeO4. Based on the fluorescence spectra related to the formed OH amounts, temperature-programmed desorption and electrochemical results, it is deduced that the unprecedented photocatalytic activities are mainly attributed to the large surface area, and enhanced charge separation from the chitosan as well as its promotion effects on O2 activation. Influencing factors that effect the photocatalytic efficiency of dyes, such as catalyst dose, dyes concentration, time, and the light source was also studied. More importantly, after five catalytic cycles, no evident deactivation was observed, suggesting the satisfactory stability of the investigated photocatalyst. Also, large numbers of superoxides radicals form which is the main active species participate in the degradation of acid black were analyzed using a radical trapping experiment. It is expected that our work could render navigated information for steering toward the design and applications of the CoCrFeO4-based photocatalyst with sun-light utilization for environmental remediation. [Display omitted] •CoCrFeO4-Chitosan beads photocatalysts were synthesized successfully.•The as-synthesized photocatalyst showed excellent activities for high-concentration dyes under sunlight irradiation.•The enhanced photo activities are attributed to the large surface area and enhanced charge separation.•Superoxide radicals are the major degrading species during photodegradation of acid black dye.